Screw-connection closure with tamperproof strip

ABSTRACT

In the case of screw-connection closures ( 1 ) with a pouring nozzle ( 2 ), on which a screw-connection cap ( 3 ) with a tamperproof strip ( 4 ) is placed in position, predetermined breaking point bridges ( 40 ) provided between the tamperproof strip ( 4 ) and screw-connection cap ( 3 ) are exposed to the risk of being prematurely destroyed during demoulding from the injection mould or when being placed axially in position on the pouring nozzle. According to the invention, posts ( 24 ) are arranged as restraining elements on the pouring nozzle ( 2 ). They engage in the tamperproof strip ( 4 ) prior to initial opening. The tamperproof strip ( 4 ) itself has weakened bending zones ( 43 ) in regions which are pushed outwards by the posts when being placed axially in position. The predetermined breaking point bridges ( 40 ) are arranged where the tamperproof strip ( 4 ) crosses over the lower periphery of the screw-connection cap ( 3 ) when it is being placed in position and subjected to maximum deformation. It is possible for the tamperproof strip, in addition to the weakened bending zones ( 43 ), to have elevated supporting zones ( 44 ), whereas the portions ( 45 ) located therebetween are of average height.

BACKGROUND OF THE INVENTION

The present invention relates to a screw-connection closure comprising a pouring nozzle with an external thread and at least one restraining element and a screw-connection cap having a lateral wall with internal threads, which mesh with the external thread of the pouring nozzle, and a tamperproof strip which is disposed by means of the predetermined breaking points in aligned relationship beneath the lateral wall of the screw cap and interacts with the at least one restraining element on the pouring nozzle.

TECHNICAL FIELD

Screw-connection closures with tamperproof strips have been known for many years. The tamperproof strip provides evidence that the contents of the container, which are closed by the corresponding screw-connection closure, are intact. The tamperproof strip is accordingly often referred to as an initial opening warranty. Screw-connection closures of this kind have been known from the prior art for many years. The problem has, however, also been recognized for the same amount of time that the tamperproof strips have already been destroyed when being removed from the injection mold or when mounting the screw-connection closure to the pouring nozzle. The main problem is that the connection of the tamperproof strip to the lateral wall of the screw-connection closure takes place via very fragile predetermined breaking point bridges. A multiplicity of solutions has been proposed to solve this problem. On the one hand, the predetermined breaking point bridges were designed substantially wider than they are thick, so that the bridges have the form of belts. In addition, raised portions were applied to the tamperproof strip in order to absorb the pressure forces when fitting the screw-connection cap and thus prevent a squeezing of the predetermined breaking point bridges. In this regard, reference can, for example, be made to the American patent specification U.S. Pat. No. 4,572,387.

Systems are also known from the prior art in which elements directed radially outwards and inwards are present on the tamperproof strip and the pouring nozzle part and slide over one another in a ratchet-like manner. The systems have, however, not solved the problem and precisely those systems which operate with a ratchet-like element particularly lead to the frequent destruction of the predetermined breaking point bridges.

In the case of known screw-connection closures made of plastic and having a tamperproof strip, the tamperproof strip has an annular retaining bead which engages behind a corresponding retaining bead or an annular groove on the pouring nozzle part. When assembling such screw-connection closures, the screw-connection cap is aligned with the tamperproof strip via the pouring nozzle and moves accordingly axially downwards, wherein the internal thread of the screw-connection cap slides over the external thread of the nozzle in a ratchet-like manner. In so doing, the tamperproof strip is expanded around the thickness of the retaining bead, wherein relatively large forces are required. During this operation, the predetermined breaking points are on the one hand compressed together and on the other hand displaced radially outwards due to the expansion around the retaining bead. A portion of the predetermined breaking point bridges is often destroyed in the process. Appropriate monitoring must therefore take place in order to remove scrap material from the production line.

Damage to the predetermined breaking point bridges also occurs during the production of such screw-connection closures with a tamperproof strip. The retaining bead has to be pulled out of the corresponding groove of the injection mold core and the predetermined breaking point bridges are correspondingly stretched. Damage to the predetermined breaking point bridges can thereby occur.

A further problem is that relatively large forces are required to open such plastic screw-connection closures. An alignment of the molecules takes place in the predetermined breaking point bridges which are of very thin design, and the tensile strength of the predetermined breaking point bridges increases accordingly. In the solutions known to date, all of the predetermined breaking point bridges are stretched at the same time and thus the resulting forces are great. This problem was recognized and a corresponding solution emerged from the WIPO patent application WO 02/102678. In this case, the tamperproof strip is disposed conically inclined to the outside so as to extend under the lateral wall of the cap, and recesses are disposed between the predetermined breaking point bridges. One or a plurality of cutting edges is affixed to the nozzle which in the assembled state protrudes outwardly through the predetermined breaking point bridges; and when the screw-connection cap is twisted off, the predetermined breaking points are consecutively cut off. Up until now, this solution has not gained acceptance in the market because the tamperproof strip protruding conically to the outside causes problems in the relative filling plants. The restraining elements on the pouring nozzle also require in this case that the tamperproof strip expands in the region near the predetermined breaking point bridges. Predetermined breaking point bridges have therefore already been destroyed during assembly.

SUMMARY OF THE INVENTION

It is now the aim of the present invention to provide a solution, which largely prevents the aforementioned problems.

This aim is met by a screw-connection closure of the type mentioned above by virtue of the fact that three to five restraining elements oriented radially outwards in the form of posts are disposed on the nozzle. The restraining elements have restraining surfaces which make contact at least in the opening direction and interact with abutment faces disposed on the tamperproof strip, wherein the tamperproof strip has one bending zone, which reduces the cross-section of the tamperproof strip, in each region adjoining the abutment faces thereof. The aim is furthermore met by virtue of the fact that the predetermined breaking point bridges are disposed away from the bending zones to an extent that a relative displacement does not occur here when the tamperproof strip is deformed.

BRIEF DESCRIPTION OF THE DRAWINGS

Different preferred embodiments of the subject matter of the invention ensue from the dependent claims and the importance and effect thereof are explained in the following description with reference to the attached drawings.

A preferred embodiment of the subject matter of the invention is depicted in detail in the drawings as well as several preferred variants. In the drawings:

FIG. 1 shows the screw-connection closure in the assembled state in a perspective depiction, while

FIG. 2 shows the nozzle depicted by itself in the lower region thereof, the depiction again in a perspective view.

FIG. 3A is a partial view of the tamperproof strip as seen from the outside depicted in a development drawing and

FIG. 3B is the same partial view of the tamperproof strip as seen from the inside.

FIG. 4 shows a partial view of the lower periphery of the screw-connection cap when the screw-connection cap is being placed on the nozzle and subjected to maximum deformation.

FIG. 5 shows a cutaway partial view of the assembled screw-connection closure in the region of the connection between nozzle and tamperproof strip, while

FIG. 6 shows the same region in a side view instead of in a sectional view.

DETAILED DESCRIPTION

The screw-connection closure, which is denoted in its entirety with the reference number 1, comprises two separately manufactured parts which are depicted here in the assembled state. This is firstly the spout or pouring nozzle 2 and secondly the screw-connection cap 3 which is connected to a tamperproof strip 4. The spout or pouring nozzle is depicted here as a separate part having a terminal flange 22 as the flange is, for example, attached on a liquids packaging consisting of a packaging produced from multilayer film or also as the flange can be welded onto a tubular bag consisting of pure plastic film. The spout or pouring nozzle can, however, also be part of a plastic bottle, wherein the spout/nozzle practically corresponds to the neck of the bottle. The nozzle 2 consists of a cylindrical tube section 20 which is provided with an external thread 21. The terminal flange 22 is integrally formed on the lower end of the cylindrical tube section. The flange serves as the bonded connection or welded connection to the corresponding receptacle. A circumferential collar 23 can be seen just above the terminal flange 22 and is formed as one piece thereon. Restraining elements 24 protruding radially outwards and having in this case the shape of posts are integrally formed on the circumferential collar. In the example depicted here, the screw-connection closure 1 is equipped with four such restraining elements or posts 24. The number of the posts is preferably between 3 and 5. If a smaller number of posts is used, the tamperproof strip can change too much in the shape thereof during assembly that it can no longer be assured that the predetermined breaking point bridges will not incur damage. On the other hand, if the number of posts exceeds 5, the deformability of the tamperproof band is too drastically limited and in turn there is likewise the risk that the predetermined breaking point bridges will be damaged during assembly.

In FIG. 3, the tamperproof strip according to the invention is shown from the outside in FIG. 3 a and from the inside in FIG. 3 b. In both cases, the tamperproof strip is shown in a development drawing. The tamperproof strip 4 is only connected to the screw-connection cap 3 via the predetermined breaking point bridges 40. The tamperproof strip has itself sections of different height. Whereas the lowery periphery 41 runs in a plane perpendicularly to the axis of rotation of the screw-connection closure 1, the upper periphery 42 runs at three different heights. The sections having the least height form the so-called bending zones 43. The regions having the greatest height form the supporting zones 44, whereas the sections 45 are finally those zones in which the predetermined breaking point bridges 40 are disposed. Walls 46, which face radially inwards, are designed as abutment faces between which the posts or, respectively, restraining elements 24 lie in the tamperproof position prior to the initial opening, can furthermore be visibly seen laterally and directly adjacent to the respective bending zone 43 in FIG. 3 b and are indicated by dashed lines in FIG. 3. The walls serve as abutment faces for the posts and are therefore predominately provided because the tamperproof strip is designed extremely thin. If the walls of the tamperproof strip are designed thicker—except in the bending zones 43, these walls 46 facing radially inwards can be eliminated. The walls 46 optionally facing inwards are however advantageous due to the fact that the corresponding posts 24 can correspondingly be designed shorter and thereby do not have to protrude beyond the contour of the tamperproof strip 4. This can be seen most clearly in FIG. 5. In this figure, it can also be seen that the outer face 47 of the posts 24 extends on the one hand from the inside to the outside and from top to bottom in an inclined or arched manner. This design is therefore selected so that the tamperproof strip 4 does not strike against the posts when placing the screw-connection cap 3 onto the pouring nozzle 2, wherein the internal thread of the screw-connection cap and the external thread of the pouring nozzle are slid over one another in a ratchet-like manner.

As mentioned earlier, the height of the wall of the tamperproof strip is designed variably high and the different zones are thus formed. It is however by all means possible, in addition to the differences in height, to design the tamperproof strip such that the strip thickness is substantially thinner in the region of the bending zone 43 than in the other zones. With respect to the effect of this design, reference is now made to FIG. 4. This depiction shows the tamperproof strip subjected to maximum deformation upon the screw-connection cap being placed on the pouring nozzle 2. The posts 24 which cannot be seen here now push the tamperproof strip 4 to the outside in the region of the bending zones 44. The tamperproof strip 4 is thereby deformed in a somewhat square configuration. When the tamperproof strip is being deformed as previously described, the edges protrude outwards while respectively the central section is in each case stretched straight between two adjacent bending zones, whereby the tamperproof strip practically crosses over the circumference of the lateral wall 30 of the screw-connection cap 3 to the left and right of the bending zones. These intersection points now define the location whereat the predetermined breaking point bridges 40 are disposed. Practically no translational relative movement occurs in this region between the tamperproof strip 4 and the screw-connection cap 3. As soon as the tamperproof strip is guided over the posts 24, the tamperproof strip reshapes again into the original form. The deformation shown in the figure is, of course, depicted in an exaggerated manner. The effect taking place is however correctly reflected.

When positioning the screw-connection cap 3 on the pouring nozzle 2, it may also occur that the tamperproof strip comes in contact with the terminal flange 22 or with the shoulder of the bottle in the event that the pouring nozzle 2 is directly part of a bottle. In so doing, a certain shortening of the predetermined breaking point bridges 40 takes place. The elevated supporting zones 44 thereby ensure that the predetermined breaking point bridges 40 are not completely compressed together and in so doing become bent. This effect can be additionally reduced by the predetermined breaking point bridges 40 being designed longer than the distance between the top edge of the tamperproof strip section having the maximum height 44 and the bottom edge of the screw-connection cap 3. In this regard, there are particularly two variants which are already known in the prior art. The first of these occurs by the tamperproof strips being disposed so as to extend in an inclined manner as is shown in FIGS. 3 a and b to the right of the bending zone. A second variant consists of the predetermined breaking point bridges 40 being designed somewhat arched to the inside.

As previously mentioned above, the pouring nozzle 2 can form the neck of a plastic bottle; and in this case, the posts 24 are integrally formed on the neck. In the drawings, only solutions are, however, depicted in which the pouring nozzle 2 is provided with a flange 22 for connecting by means of welding or adhesive bonding to a flexible receptacle; and in this case the aforementioned posts 24 are integrally formed on the spout or pouring nozzle as especially can be seen in FIG. 3. 

1. A screw connection closure (1) comprising a pouring nozzle (2) with an external thread (21) and at least one restraining element (24) and a screw-connection cap (3) having a lateral wall (30) with internal threads, which mesh with the external thread (21) of the pouring nozzle (2) and a tamperproof strip (4) which is disposed by means of predetermined breaking points (40) in aligned relationship beneath the lateral wall of the screw-connection cap (30) and interacts with the at least one restraining element on the pouring nozzle, characterized in that three to five restraining elements (24) directed radially outwards are disposed on the pouring nozzle in the form of posts which have restraining surfaces that make contact at least in an opening direction and interact with abutment faces disposed on the tamperproof strip (4), wherein said tamperproof strip (4) has one bending zone (43), which reduces a cross-section of said tamperproof strip, in each region adjoining the abutment faces thereof, and in that furthermore predetermined breaking point bridges (40) are disposed laterally away from the bending zones (43) to an extent that a substantial relative displacement does not occur here when the tamperproof strip (4) is deformed upon placing the screw-connection cap (3) on the pouring nozzle.
 2. The screw connection closure (1) according to claim 1, characterized in that the tamperproof strip comprises sections having three different heights, wherein a lower periphery (41) of the tamperproof strip (4) runs in a plane perpendicularly to the an axis of rotation of the screw-connection closure (1).
 3. The screw connection closure (1) according to claim 2, characterized in that the sections having a least height form the bending zones (43); the sections of average height (45) form regions in which the predetermined breaking point bridges (40) are disposed; and the sections with the a greatest height form the supporting zones (44).
 4. The screw connection closure (1) according to claim 3, characterized in that walls (46), which face radially inwards, are designed as abutment faces and between which the posts (24) lie in a tamperproof position prior to the initial opening, laterally and directly adjoin the bending zones (43).
 5. The screw connection closure (1) according to claim 4, characterized in that the posts (24) protrude radially outwards to an extent that outermost ends thereof at most align at least approximately with an outer surface of the tamperproof strip (4).
 6. The screw connection closure (1) according to claim 3, characterized in that the predetermined breaking point bridges (40) are longer than a distance between a top edge of a tamperproof strip section having the greatest height and a bottom edge of the lateral wall of the screw-connection cap.
 7. The screw connection closure (1) according to claim 6, characterized in that the predetermined breaking point bridges extend in an inclined manner.
 8. The screw connection (1) according to claim 6, characterized in that the predetermined breaking point bridges extend inwardly in an arched manner.
 9. The screw connection closure (1) according to claim 5, characterized in that the posts (24) each have an outer face (47) which extends from an inside to an outside and from top to bottom in an inclined or arched manner.
 10. The screw connection closure (1) according to claim 1, characterized in that the tamperproof strip (4) has regions with different wall thicknesses, the wall thickness being the least in regions of the bending zones (43).
 11. The screw connection closure (1) according to claim 1, characterized in that the pouring nozzle (2) forms a neck of a plastic bottle, on which neck the posts (24) are integrally formed.
 12. The screw connection closure (1) according to claim 1, characterized in that the pouring nozzle (2) is provided with a lower marginal flange which is suited for connecting to a tubular bag. 